There used to be a lot of different things done to try a beef up parts for performance use that shouldn’t be attempted in this day and age. While I believe for “general” performance usage, preparing the crank as listed above will help; stronger rods are easily available for the 4.3V6. You may have to have the sides of the rods machined for use in a V6, but beings they are still basically a 350 minus a couple of cylinders, you have a wide selection available and any competent machine shop should be able to handle the rest. At a bare minimum, have the rods magnafluxed, peened and good rod bolts installed.

Way back in the day, people would plate in the sides of steel rods; this would involve cutting plate to the shape of the sides of the rods and welding them out. Unfortunately, they would end up with a bunch of bent rods from the welding unless extreme care was used in the process and in a lot of cases even if they did use care. Rods are just too easy to come by now too even entertain the thought of doing so.

 

Yeah they'll have to be machined due to the journal being slightly diffrent 2.100 as opposed to the 4.3's 2.250 ( I believe ) journal.

Good information from all, Thanks greatly appreciate it.
I wonder if cry treating my nv3500 will help it stand a chance against the lq9 going in.

 

Your absolutely correct, as the rods from a small block can only be used in 1978-84 200/229ci V6 engines by narrowing the big end by aprox .050", also the bearings are .130" narrower than a traditional small block. However due to the crankshaft rod journals of the 4.3L being 2.250" diameter instead of 2.10" diameter as is the case with more traditional small blocks and older V6's, they will not work.

 

It's to bad, the 4.3 isn't that bad of an engine aside from the craptacular fuel injection spider junk on it. It's pretty much withstood TONS of abuse ( Driven it 38K in the last year ) without any problems. Good engine crappy aftermarket for it.